Atomistic Modeling and Ab Initio Calculations of Yttria-Stabilized Zirconia

Though a number of atomistic-model studies of yttria-stabilized zirconia (YSZ) have been reported to elucidate its properties, most of them have employed simple pairwise potential functions to express interactions between atoms, which limits the transferability of the models. We have developed a Tangney-Scandolo dipole model potential for YSZ. Energy, stress and forces on atoms calculated by the ab initio (first-principles) density functional theory are provided as reference data for potential fitting. The developed potential successfully reproduces cubic-tetragonal phase transition at a range of yttria concentration relevant with SOFC application. The potential can well reproduce the barrier energy of oxygen vacancy migration. Molecular dynamics simulations of oxygen diffusion in bulk and at grain boundaries are demonstrated.